1. Field of the Invention
This invention pertains generally to ventilating apparatus and more particularly to exhaust hoods for ventilating fumes from a stove, grill, or other commercial, home, or industrial work area.
2. Description of the Prior Art
Exhaust hoods such as are utilized in restaurant kitchens, industrial work areas, and the like commonly consisto of a hood enclosure, spaced somewhat above the stove, grill or other fume producing area, which draws fume laden air into the hood by means of the low air pressure produced within the hood area by an exhaust fan. Such hoods may also utilize the injection of outside air into the fume collection chamber of the hood to increase the draw of the hood to minimize the volume of tempered air withdrawn from the room. Filters are generally employed in the exhaust hood between the fume collection chamber and the exhaust chamber to substantially remove the droplets of grease, particulate matter, and the like which may be entrained with the fumes which are drawn into the exhaust hood.
If a sufficient proportion of the grease for instance is not removed by the filter, such grease will tend to collect and congeal on the exhaust ductwork of the ventilating apparatus, and around the exhaust fan opening on the roof of the building being ventilated. This collection of grease inhibits the flow of air through the ductwork and presents a substantial fire hazard. Moreover, inefficiency of the filter caused by overloading of the filter with grease and other foreign matter greatly reduces the air flow through the filter, and thus reduces the efficiency of the ventilating apparatus. Frequent periodic cleaning of the filters is required in any installation where fume laden air is being drawn into the exhaust apparatus over a substantial period of time. The cleaning of filters of grease and other matter in present ventilating systems involves manual removal of the filters by an attendant, which generally requires that the ventilating apparatus and the cooking facilities or other fume generating device which it ventilates be shut down during the cleaning operation. Such manual cleaning may substantially reduce the productivity of the operation such as cooling facilities where the grease filters may require cleaning several times a day to maintain top efficiency. Additional problems are encountered during manual removal of the filters, including, for instance, incidental dropping of accumulated grease onto the cooling area during the removal and cleaning procedure.